Treatment of aldehyde-amines



patented May 12, 19 31 7 UNITED STATES PATENT OFFICE SHERMAN I.STRICKHOUSER, OF PASSAIC, NEW JERSEY, ASSIGNOR TO THE NAUGAIUCK CHEMICALCOMPANY, OF NAUGATUCK, NECTICUT CONNECTICUT, A CORPORATION OF GON-TREATMENT' OF ALDEHYDE-AMINES s are liable to deterioration, issubstantially retarded.

'Acoordingly the invention comprises treating aldehyde-aminecondensation products that are liable to deterioration when in contactwith air, with a small amount of a poly hydroxy or substituted poly.hydroxy .aromatic body. The condensation product when so treated may betreated alone or where mixed with other substances. Notably thesecondensation products sufier deterioration where they are compoundedwith such as rubher as in the form of a master batch that awaits furthertreatment, and the invention provides a class of materials which willcheck or retard such deterioration. Typical of such materials arecatechol, resorcinol, pyrogallol, chloro hydroquinone dichlorohydroquinone, dinitroso-resorcinol, hydroquinone. Deterioration of thealdehyde-amine condensation products is manifest particularly where theyare in contact with air. Whether the deterioration is caused by trueoxidation or merely reformation of, or additions in, the condensationproduct is not definitely known, but the property of aldehyde-amines, ofabsorbing iodine provides a means of measuring the deterioration. Thefollowing examples illustrate the'invention with the condensationproduct of heptaldehyde and aniline.

10% of hydroquinone is added to the condensation product of heptaldehydeand aniline, preferably by first dissolving the hydroquinone in a smallamount of the condensation product with the aid of heat and then addingthe concentrated solution to the larger portion of condensation product.A

1929. Serial No. 355,984.

similar example of the condensation product, without the addition ofhydroquinone 18 used for comparison in the following test: The sampleshave air drawn through them for a period of 116 hrs. Iodine titration iscarried out on the aerated sample, as well as on corresponding sampleswhich have not been aerated. The iodine test is as follows: 1

There is weighed out 2 one-gram portions of the sample to be tested in100 c. c. beakers and-dissolved in 20 cc. portions of benzol. To onegram portion is added 5 c. c. of

iodine solution from a .burette, stirring for 5 seconds, and testing forthe end point by adding a drop or two of aqueous starch solut1on on aclean dry porcelain plate. 5 c. 0. portions of iodine solution arecontinuously added until the condensation product S0111? tion givesadefinite black-blue coloration with a drop of starch. When the endpoint is reached the solution isstirred about 15 seconds and retested.If the solution gives no end point at the end of the second period ofstirring another 5 c. c. of iodine should be added and tested as before.This titration serves to fix the. end point to the nearest 5 c.c.of I

starch solution. The iodine solution is added 1 c. c. at a time untilthe end point is reached,

stirring 5 seconds after such addition of iodine, and stirringBO secondslonger after the' end point is reached and retesting. If .the mixturedoes not give a definite coloration after the second period of st irringanother 1 c. 0. portion of iodine should be added, stirred for 30seconds and tested again. 1 c. c. excess of iodine solution should givean intense black coloration around the edge of the drop of starch paste.The following reference to iodine titration are-expressed as ten timesthe number of=c. c. of

iodine absorbed per gram oi aldehyde-amine condensation product. 7

Another method of testing is to vulcan'ize rubber with the condensation;productrbefore and after aeration and measuring the tensiles. Dataobtained by these methods showing the protective action of hydroquinoneare given below.

Aerated and nnaemted condensation.product concentration of hydroqninoneBlank V Original titer; 4G5 465 445 435 Titre after 116 hrs aeration259, 305 369 389 Per cent loss 34. 4 17.1 10. 5 Per cent of originaltitre 65. 6 82. 9 so. 5

Tcnsilcs of rubber containing .05% of condensation product concentrationof hydroqninone Blank 30 at 403 at start 2, 010 2 190 2, 445 2, 300After aeration (115 hrs.) 1, 555 1,500 2, 060. 2,175 GOat 40,; at start2, 460 2, 340 2,335 2, Q After aeration (116 hrs.) l, 820 2, 260 2,415loss (average) 2" 2638 9.3- 5L4 of original accelerating value(average); 73. 7 73. 2 90. 7 9- 6 The aldehyde amines which are subjectto deterioration when in contact with a1r,'w'hen treated with a smallamount'of' a.-polyhy:-

droxy or substituted poly hydroxy substance, may be stored as such, orwhen present in a master rubber batch, be kept for a substantialperiod,with.1ittle impairment of their qualities.

With the above detailed disclosureof, the invention it is evident thatnumerous modifications will suggest themselves to those skilled in theart, and' it is not desired to limit the invention otherwise than as setforth in the appended claims.

Having thus described my invention, what I claim'and desire to protectby Letters-Patentjisr 1. The method of retarding the deterioration ofaldehyde-amine condensation produnits which comprises treating saidproducts with a poly hydroxy aromatic body.

2; The method of, retarding the deteriora tion of aldehyde-aminecondensation productsin rubber batches which comprises mixwithhydroquinone;

Themethochof retardingthe deterioration of: aldehyde-amine condensationproclucts in rubber batches Which comprises mixin-g said-products withrubber in the presence ofihydroquinone.

7-. The-method ofretarding the deterioration. of a heptaldehyde-anilinecondensation productzwhich comprisestreating said prodnot: with apolyhydroxy aromatic body.

8. The-method of retarding the deterioration off a. heptaldehyde'aniline condensation product in rubber batches which comprisesllllXlllgbSftld product; with rubberz in the-presence of a polyhydroxyaromatic body.

9.- The: method of ret'ardingthe deterioration ofi aheptaldehyde-aniline condensation product/which comprises. treating saidprodnct'with hydroquinone.

10. The method of retarding the deterioration of. heptaldehyde anilinecondensation product. in rubber batches which comprises mixingsaidiproducts with rubber in the presence offihydroquinone.

11 As a new. product. an admixture containing analdehyde-aminecondensation product and a poly. hydroxy aromatic body.12. As anew product an admixture cont-aining an aldehyde-aminecondensation product and a substituted poly. hydrox-y aromatic body.

'13. Asa; new: product an admixture conta ning an aldehyde-aminecondensation product and hydroquinone.-

14-41 As; a. new product. an admixture containinga1heptaldehydeanilinecondensation productiand a-poly.hydroxy-aromatic body.

Signed'at Passaic, county. of Passaic, State of New Jersey, this 12 day,ofApril, 1929.

SHERMAN I. STRICKHOUSEB.

